1. Field of the Invention
The invention relates to the field of automatic identification, which includes indicia recognition technologies such as bar code, magnetic stripe, touch memory, smart card, Magnectic Ink Character Recognition (MICR) and optical character recognition as some the more prevalent mediums of identification.
2. Related Art
It is known in the art of automatic identification to interface individual ones of various types of reading devices to notebook PC's (Personal Computers) and desktop PC's through the serial port, keyboard port, or game port with hardware decoders transmitting the standard formats to these ports. Examples of the types of reading devices interfaced in this manner include, e.g., bar code laser, CCD, and wand; touch button wand; and magnetic stripe readers.
Most prior art bar code applications and other data collection applications for the IBM PC/XT/AT or compatibles require use of a dedicated hardware device. Such a device normally must have a microprocessor and built-in software which can receive and decode the signals from the mentioned data reading devices and send the decoded data to the PC. Most of these devices povide only one input for the data reading devices in order to lower hardware costs. Further, many of these applications communicate with the PC through the keyboard interface, which requires that the PC keyboard be connected to an external hardware device. This limitation prevents use of such interfaces by most notebook PC's, which do not have keyboard connectors.
Prior art methods and apparatuses for interfacing automatic identification readers to notebook PC's and PC's carry with them several drawbacks and restrictions. First, the serial port is in very high demand for communication purposes by a host of devices, many not even related to automatic identification, such as the mouse. And, many notebook computers contain only a single serial port for interfacing to external serial devices. Second, the prior art devices often require an external decoder box to be attached to the notebook PC and/or PC, which in the case of the notebook PC seriously encumbers its intended portability. Third, different types of reading devices and multiple devices of the same type are often needed to be used on one PC or PC notebook, and such applications are not adequately enabled by the prior art. For example, in point-of-sale applications a magnetic stripe for credit card transactions and one or more bar code readers for checking out products often need to be supported by a single PC. However, the prior art does not provide adequate means for interfacing multiple reading devices to a PC using a single port, i.e., the serial or the parallel port. Fourth, external hardware decoder devices or RS-232 reading devices with built-in decoders, such as CCD or laser scanners, commonly consume more power and often require external power supplies attached to AC outlets, making them immobile. Fifth, when a high-power-consumption reader cannot be substituted by a lower-power-consumption reader, providing that power with the tether to AC outlets hinders portability.
Further disadvantages of prior art automatic identification systems include high hardware costs, low bar code or magnetic decoding speed, limited capability of editing decoded data, and low flexibility of programming the device.
The most common connection provided by the prior art between barcode scanner and computer is the "Wedge" interface. Specifically, two types of Wedge are commonly used: "Keyboard Wedge" and "RS-232 ASCII Wedge". Both types are microprocessor-based bar code decoders which receive "raw" barcode signals from a scanner and output decoded information signals directly readable by a PC. The former type emulates the operation of the keyboard by sending the resulting code to the keyboard port of the computer. And, that type normally requires that the output cable of the Keyboard Wedge be connected to the PC keyboard connector and the PC keyboard be connected to the Wedge. As set forth above, most notebook computers can never be connected to the external Keyboard Wedge. The RS-232 ASCII Wedge-type interface translates the resulting code to ASCII code, which is sent to the computer via RS-232 or RS-422 port. However, the RS-232 ASCII Wedge requires use of communication software on the PC to receive and store the data from the port. As most data processing applications normally receive input throught the PC keyboard, they require use of a special TSR program which can receive the decoded data in ASCII format from the serial port and cause the data to emulate keyboard input.
As notebook PC's become more and more popular in the automatic identification area, the prior art technology is no longer adequate for many data collection applications.